基于ptlib更新日志

bool  Gatekeeper::RotateLogFile()
... {
    PWaitAndSignal lock(m_logFileMutex);

    if (m_logFile) ...{
        PTRACE(1, "GK Logging closed (log file rotation)");
        PTrace::SetStream(&cerr); // redirect to cerr
#ifndef hasDeletingSetStream
        delete m_logFile;
#endif
        m_logFile = NULL;
    }

    if (m_logFilename.IsEmpty())
        return false;
    
    PFile* const oldLogFile = new PTextFile(m_logFilename, PFile::WriteOnly, 
        PFile::MustExist
        );
    if (oldLogFile->IsOpen()) ...{
        // Backup of log file
        PFilePath filename = oldLogFile->GetFilePath();
        const PString timeStr = PTime().AsString("yyyyMMdd_hhmmss");
        const PINDEX lastDot = filename.FindLast('.');
        if (lastDot != P_MAX_INDEX)
            filename.Replace(".", "." + timeStr + ".", FALSE, lastDot);
        else
            filename += "." + timeStr;
        oldLogFile->Close();
        oldLogFile->Move(oldLogFile->GetFilePath(), filename);
    }
    delete oldLogFile;
        
    m_logFile = new PTextFile(m_logFilename, PFile::WriteOnly, PFile::Create);
    if (!m_logFile->IsOpen()) ...{
        cerr << "Warning: could not open the log file ""
             << m_logFilename << "" after rotation" << endl;
        delete m_logFile;
        m_logFile = NULL;
        return false;
    }

    m_logFile->SetPosition(0, PFile::End);
    PTrace::SetStream(m_logFile);
    PTRACE(1, "GK Logging restarted.");
    return true;
}

该函数实现的功能是将老日志文件修改名称为“名称+日期”，新日志文件继续记录日志